	* {
	  margin: 0;
	  padding: 0;
	}

	html,
	body {
	  height: 100%;
	  width: 100%;
	}

	div {
	  width: 200px;
	  height: 200px;
	  margin-top: 100px;
	  background-color: #DCDFE6;
	  border: 2px solid #909399;
	  float: left;
	  border-right: none;
	  display: flex;
	  box-sizing: border-box;
	  /*=== 怪异盒模型 padding 和 border值不算入宽高 ===*/
	  justify-content: center;
	  /* 主轴对齐方向 */
	  align-items: center;
	  /* 侧轴对齐方式 */
	}

	div:nth-child(6) {
	  border-right: 2px solid #909399;
	}

	div:nth-child(1) {
	  margin-left: 200px;
	}

	div span {
	  width: 50px;
	  height: 50px;
	  display: block;
	  border-radius: 50%;
	  background-color: #F56C6C;
	  color: white;
	  text-align: center;
	  line-height: 50px;
	  cursor: pointer;
	}

	div:nth-child(1) {
	  justify-content: center;
	  align-items: center;
	}

	div:nth-child(2) {
	  justify-content: space-around;
	  align-items: center;
	}

	div:nth-child(3) {
	  justify-content: space-around;
	  align-items: center;
	  padding: 10px;
	}

	div:nth-child(3) span:nth-child(1) {
	  align-self: flex-start;
	  /* 子元素排列方式 */
	}

	div:nth-child(3) span:nth-child(3) {
	  align-self: flex-end;
	}

	nav {
	  width: 200px;
	  height: 50px;
	  /* background-color:firebrick; */
	  display: flex;
	  justify-content: space-around;
	}

	div:nth-child(4) {
	  flex-wrap: wrap;
	  /* 是否允许换行 */
	}

	div:nth-child(5) {
	  flex-wrap: wrap;
	  padding: 10px;
	}

	div:nth-child(6) {
	  flex-wrap: wrap;
	  padding: 10px;
	}